Brine injection method for oil wells



Oct. 28, 1941; R. w.-ERwlN y 2,261,100

BRKNEA INJECTION METHOD FOR OIL-WELLS v i 4Filed July 25, 1941 A @awsome mgm/'12 IN VENTOR.

' 7 UNIT-Bof :rAraNT OFFICE mi 2,26i,1oo

BRINE INJECTIONMETHOD FOBOILWELLS v Bancone-W. Frwin, 'Lontvlm Tex), anim to vSalt Water vContro Inc., Ft Wortll, '.lex., a mcorpontion Application July 25,' 1941, Serial No. 404,094

A ((1168-21) This invention relatesvto improvements in liquid y although other emulsion treating apparatus may injection systems for oilwellsandthe like. 's 1 be used if desired. The output from a well in- -In my application Serial No. 345,688 filed July cluding the total oil, emulsion, gas and water 15, 1940, I havedescrlbed vand-claimed abrirle 'y enters the unit A'-2 through the line or pipe 'I injectionsystem 'somewhat 'diiierent in ldetail 5 and the-treated oil ilows from the unit to stock from that .disclosed in the present applical.tion,y tanks through the line 48. though embodying the 'same broadmethod'steps. Connected intothe system is an oil skimmer In my application Ser. No.l v-il( )4;095 illed July25. y tank 3, a surgetank llas lift cylinder ,the 1941-, I have described andclai'med an `emulsion latter being connected .to a wire line 32 having treating apparatus .whichfmayvv or may not be l0. weightbar llen'closed in a tubing 6. The tubing used in conjunction withthe injection-system of isfplaced'i'n a wellcasing-l wherein there is a the present application.' i' .-NQ ccntloljvalve"IS'and-a-'packer- 36. The 'system The primary object ofthe inventionjis-theprof. 1 i'ncludesxa back-.wash pitline 44, a gas pressure vision ofla system of. this vcharacter 'which will f1, 'line'Q-'Lanoil ow'line and a brinewater line, easily adaptitself .forfinstallation'witlinyitype l5 including various valves and parts' which will of closed gas-tight'crudejoil. emulsl'on .treating bereferreditohereinaiterf'in detail..V system an'd'which 'will also- .providefal:.crystal l The. system no chemicals whateverand clear crude petroleum or-1 .disp0sal'l n=a 'prv'ldes water that ymix 'with formation suitable disposal we waters iwrithoutA precipitationsfwhich 'are caused Another'. object of'- when excessively' treated waters (withoxidyzing a system which will` agents irlexcess in them) are mixed with native" sufllcientlystable" g formation waters. No special alloys `areused. its dissolved minera because unaerated brine being 'handled 4is. noncorrosive, andthe lsystem is entirely salvageable, .automatic and demands a i'minimumvof attention. As depictedinthe drawing, the complete travel .ff oi the brine through the system is as follows the-brinezleaves any emulsion treating unitrA-f- I at thezbottom as shown atfA; it goes out and vup ovr'rlthe'adjustabie waterl legs 2`or any? other suitable level control which maintains an auto-k matic Soil-waterlevel in thetreater.' 'Gas lockv vand;sypliox iseal are prevented; bythe exible i ,gas eiiuali'zing metal hosefll on'these'waterlegs. y olume 35'15'Ili'ewater proceeds to the point 13v whereit'may in order 'to reduce retentionjperiodffoi,'water. y `feithenli'ese'nt to' a back-'washgpit throughl the thereby vsuppressinggrowth;- o f-harn iu l ..bacteria valve 2|..` or on its normal course .through the rcultures, and provides :automatic arrangements .valve` I8. Through -valve il it entersl the oil to take carefof any and alltypes .of emergencies skimmertank-B at the pointy C. vAnyoil accumuthat could occur inrelation to 'a idisposalfwell. y40: lating at this pointis automatically removed by The system and method'vhereinaiter described `gravity atl D whence it goes through the liquid in detail embody a controlled `valve arrangement g seal dump valve I1 and on to stock tank or burn- -in the disposal well that.bringsabout acondltion ing pit. 'I'he water goes on down through this whereinthe disposal well remains'riull: 0 1- brine vupper oil skimming chamber through the dished at all times, and provide a controlledval've'ar'- '45 bottom `at E where it may either vbe directed rangement in the disposal-well such A'that the through the ilter chamber at the bottom by well takes water at its full capacity at 'any time passing through the valves 20 and I9 and out at that any water is being introduced therein. F or it may be allowed to by-pass the lower In the drawing accompanying this speciilca-l chamber by going through the valve 22. Thus, tion are shown in schematicdiagram the various 50 if it is desiredv to change the excelsior lter in parts embodied in the system and method and the lower chamber this chamber may be comwherein as lat A-2 is shown a tank which may pletely isolated, allowing the water to by-pass it -represent any closed gas-tight emulsion treating and go on -to the disposal well. By proper maumu This may be of the type disclosed in my@ nipulation of the valves I8. I9, 20, 22 and 2l and application' Ser. No. 404,095, tiled July 25, 1941, 55 the valve I1 it is possible to -use water in the y to do, 'sojthat said' water` y-in `disposal ,.sand witho otherwise causedby convey ing' agents in thei'treate a vrequires nofchem'ical whatever vides a system ofjcomparativ y upper skimmer chamber for back-washing the filter section in the lower chamber, sending the waterto the back-wash pit through the line 44. In normal operation the water leaves the lower iilter chamber at F and on to G up through the valve 23 and over the water legs 25 atH. These legs are gas-equalized with flexible metal hose 24. The water goes on back down leg and enters the surge tank 5 at the-point K. vThis tank acts important function oi this tank is to provide a volume range of water for the well so that the wireline control valve 35 ywill not have to function so often. 'Ihe Water leaves this tank and enters the casing I through valve 53 of the injection well at the point L (it may also enter tubing 6 at the point O through valve 54 at the same time as it enters the casing 4, or may enter tubing I only). It goes on down the casing ,l and through the control valve ports P at the point M which admits water through the packer 36 and allows it to go on downinto the disposal sand.

For the sake of most 'eiiicient operation this packer 36 should be located at or below the static level of the'well in order tovprevent formation `of vacuum below the packer during the periods when the tubing valve 35 is closed. vIf for some reason the valve 35 in the well fails to open or the well refuses to take all of the water, then the level will .build up'in the water legs of the skimmer tank 3, the water finally overflowing at the point N where it goes through the liquid seal 43 and to the back-wash pit. It should be noted that in this case the normal level 50 in ing or tubing into the disposal sand. It has been shown experimentally that calcium, magnesium and iron compounds precipitate to a certain degree from un-aerated crude petroleum brine when it is subjected to a vacuum or cascading, thereby permitting a partial temporary dissolution of carbon dioxide from the s upersaturated bicarbonate system of minerals, this said dissolution renderingv them partially insoluble. Under the conditions involved, this reaction is nonreversible even though the carbon dioxide is never lost from the system once it enters the 'disposalwelL In the'system of the present invention un-aerated water that is not flashed, expanded, or cascaded after it leaves the last filter remains crystal clear and experiment shows that it. will not plug the disposal sand. Ainwith its damaging oxygen v is completely excluded vby keeping the total system under a few pounds pressure at all times, and in the system and method here involved are provided absolutely corrosion-proof means for carrying out the purpose of the invention. Further, vthe system is strictly automatic and the only maintenance required is a change of excelsior (one bale) every.

l ing system and method inline with'the principle the tank 5 would build on up in the gas vent through release valve 29 until point N in the water legs is reached. The valve -35 in the well is actuated by the wire line 32, in the tubing 6,

This wire line is actuated by gas-powered piston-cylinder 30, and the and the weight ba'r 3i.

piston is moved by gas from motor valves 21 and 2l which admit and exhaust pressure gas that is procured from the gas source shown at the extreme right of the diagram. The cylinder motor valves are actuated by hydraulic pressure from the line between the surge tank 5 and the well through the valve 26. Thus, when the level builds up in the surge tank to the point 50 where the injection valve needs to open and admit water to the disposal sand, this head acts through valve 25 on the motor valve 28 which admits power gas to the cylinder, thereby lifting the.

wire line and the weight bars and allowing spring S to open the valve over the packer 36. When the level in the surge tank falls to the minimum point 5| which is above inlet K in surge tank 5, the motor valve 21 is actuated to open and exhaust power gas from cylinder, thus allowing the weight bar and the wire line to drop and close the disposal valve above the packer.

From the foregoing it will be apparent that if a lease is producing five barrels output per hour or five hundred barrels per hour, the brine disposal well remains completely full of water at all times, thus avoiding the dangerous procedure of flashing water and cascading it down the casinvolved in the invention, it is of course understood that variations and alterations may be made therein which will be within the range and scope of the claims appended hereto.

I claim:

1. An injection method for oil ilelds and the like which comprises introducing liquid into the upper portion of a well having a porous formation at the bottom thereof from an external source whose level is maintained above the level of the well. and controlling the flow of liquid through the well to said porous formation from a point in the well substantially below the point of introduction in accordance with variations in the level of said source to maintain a substantially continuous column from said formation to said source, thereby avoiding cascading.

2. An injection method as set forth in claim 1 wherein the liquid introduced into the well is brine separated from an oil and water emulsion.

3.An injection method as set forth in claim 1 mittent.

4. In a liquid disposal system for oil fields and the like including a disposal wellhaving a porous formation at the bottom thereof; an external source of liquid having a variable liquid level and a pipe connection leading from said source to the upper portion of said disposal well, a packer in said well intermediate the porous formation and the point of introduction of liquid, and means for maintaining a substantially continuous column of liquid from the porous forma-` tion to said source to avoid cascading; said means including a normally closed valve co-acting with an opening in said packer, mechanism actuated by the raising of the liquid level in said external source to a predetermined point for opening said 

